Carvalho B.O.,Institute Biologia |
Carvalho B.O.,Instituto Leonidas e Maria Deane |
Lopes S.C.P.,Institute Biologia |
Nogueira P.A.,Instituto Leonidas e Maria Deane |
And 19 more authors.
Journal of Infectious Diseases | Year: 2010
Background. Plasmodium falciparum and Plasmodium vivax are responsible for most of the global burden of malaria. Although the accentuated pathogenicity of P. falciparum occurs because of sequestration of the mature erythrocytic forms in the microvasculature, this phenomenon has not yet been noted in P. vivax. The increasing number of severe manifestations of P. vivax infections, similar to those observed for severe falciparum malaria, suggests that key pathogenic mechanisms (eg, cytoadherence) might be shared by the 2 parasites. Methods. Mature P. vivax-infected erythrocytes (Pv-iEs) were isolated from blood samples collected from 34 infected patients. Pv-iEs enriched on Percoll gradients were used in cytoadhesion assays with human lung endothelial cells, Saimiri brain endothelial cells, and placental cryosections. Results. Pv-iEs were able to cytoadhere under static and flow conditions to cells expressing endothelial receptors known to mediate the cytoadhesion of P. falciparum. Although Pv-iE cytoadhesion levels were 10-fold lower than those observed for P. falciparum-infected erythrocytes, the strength of the interaction was similar. Cytoadhesion of Pv-iEs was in part mediated by VIR proteins, encoded by P. vivax variant genes (vir), given that specific antisera inhibited the Pv-iE-endothelial cell interaction. Conclusions. These observations prompt a modification of the current paradigms of the pathogenesis of malaria and clear the way to investigate the pathophysiology of P. vivax infections. © 2010 by the Infectious Diseases Society of America.
Cristina Ferreira Silva L.,Fundacao de Medicina Tropical do Amazonas |
Espinosa Miranda A.,Federal University of Espirito Santo |
Santos Batalha R.,Fundacao de Medicina Tropical do Amazonas |
Sabino C.,Fundacao de Medicina Tropical do Amazonas |
And 4 more authors.
Brazilian Journal of Infectious Diseases | Year: 2012
This was a cross-sectional study aimed to determine the prevalence of and to identify risk factors for Chlamydia trachomatis (CT) among human immunodeficiency virus (HIV)-infected women attending the acquired immunodeficiency syndrome (AIDS) clinic in the city of Manaus, Brazil, in 2009-2010. Participants answered a questionnaire containing demographic, epidemiological, and clinical data. A genital specimen was collected during examination to detect CT-DNA by hybrid capture, and blood samples were taken to determine CD4+T and HIV viral load. There were 329 women included in the study. Median age was 32 years (IQR=27-38) and median schooling was nine years (IQR=4-11). The prevalence of CT was 4.3% (95%CI: 2.1-6.5). Logistic regression analysis showed that age between 18-29 years [OR=4.1(95%CI: 1.2-13.4)] and complaint of pelvic pain [OR=3.7 (95%CI: 1.2-12.8)] were independently associated with CT. The use of condom was inversely associated with CT [OR=0.39 (95%CI: 0.1-0.9)]. The results showed that younger women who did not use condoms are at a higher risk for CT. Screening for sexually transmitted infections must be done routinely and safe sexual practices should be promoted among this population. © 2012 Elsevier Editora Ltda.
PubMed | Fundacao Osvaldo Cruz, National Institute of Amazonian Research, EMBRAPA - Empresa Brasileira de Pesquisa Agropecuária, Fundacao de Medicina Tropical do Amazonas and Federal University of Amazonas
Type: Journal Article | Journal: Genetics and molecular research : GMR | Year: 2014
Guarana has great agricultural potential and is largely used therapeutically and in the production of non-alcoholic energy drinks. Genomic and proteomic studies are crucial to identify proteins that play central roles in the maintenance and viability of fruits, as well as to identify proteins related to the main metabolic pathways. However, the success of any protein analysis starts with the protein extract preparation, which needs to offer an extract that is free of contaminants. This study aimed to evaluate different extraction methods to obtain high-quantity and high-quality extracts that are compatible with analysis by 2-dimensional electrophoresis and tandem mass spectrometry protein identification. Three different methods were tested: trichloroacetic acid (TCA)/acetone, sodium dodecyl sulfate (SDS)/phenol, and polyvinylpolypyrrolidone (PVPP)/SDS/phenol. The extract obtained from the TCA/acetone precipitation presented low solubility and contamination with lipids and carbohydrates. On the other hand, the quality of the extract gradually improved after using phenol and PVPP/phenol, enabling a yield up to 2 mg/g macerated tissues and the detection of 457 spots by 2-dimensional electrophoresis. The effectiveness of the procedure used was validated by identification of 10 randomly selected proteins by mass spectrometry. The procedure described here can be a starting point for applications using tissues of other organs of guarana or tissues of species that are similar to guarana.
Khell Da Silva B.,Fundacao de Medicina Tropical do Amazonas |
Freire A.K.,Fundacao de Medicina Tropical do Amazonas |
Dos Santos Bentes A.,National Institute of Amazonian Research |
De Lima Sampaio I.,Fundacao de Medicina Tropical do Amazonas |
And 3 more authors.
Revista Iberoamericana de Micologia | Year: 2012
Background: The differentiation and classification of pathogenic Cryptococcus species provides useful data for epidemiological studies and for the clinical diagnosis and treatment of patients. Aims: The aim of this study was to characterise 40 clinical Cryptococcus isolates obtained from patients at the Tropical Medicine Foundation of Amazonas (FMTAM) from 2006 to 2008. Methods: It was used phenotypic (i.e., enzyme production and antifungal resistance) and molecular biological (URA5-RFLP) experiments. Results: Patients with HIV/AIDS were most affected with cryptococcosis. Thirty-one (75.5%) of the clinical isolates were classified as Cryptococcus neoformans and 9 (22.5%) as Cryptococcus gattii. High amounts of protease and phospholipase enzymes were produced by most of the isolates. Using the disk diffusion test (CLSI M44-A), 81, 35 and 100% of the C. neoformans isolates were characterized as susceptible to fluconazole, itraconazole and amphotericin B, respectively, whereas 78, 56 and 100% of the C. gattii isolates were susceptible to these antimicrobial agents. The average of Minimal Inhibitory Concentration (MIC) for C. neoformans and C. gattii isolates was 0.26 and 0.58 μg/mL, respectively. The 9 isolates of C. gattii had a fingerprint pattern comparable with the VGII molecular type, while all 31 isolates of C. neoformans presented with a pattern consistent with the VNI type. Conclusions: This study confirms the importance of HIV/AIDS for the cryptococcosis epidemiology, the susceptibility of the isolates to amphotericin B and the high prevalence of the molecular genotypes VNI and VGII in the north of Brazil. © 2010 Revista Iberoamericana de Micología.
Chrusciak-Talhari A.,University Estadual do Amazonas |
Dietze R.,Federal University of Espirito Santo |
Talhari C.C.,Fundacao de Medicina Tropical do Amazonas |
Da Silva R.M.,Fundacao de Medicina Tropical do Amazonas |
And 4 more authors.
American Journal of Tropical Medicine and Hygiene | Year: 2011
Miltefosine has been used in the treatment of several new world cutaneous leishmaniasis (CL) species with variable efficacy. Our study is the first evidence on its clinical efficacy in Leishmania ( Viannia ) guyanensis. In this phase II/III randomized clinical trial, 90 CL patients were randomly allocated (2:1) to oral miltefosine (2.5 mg/kg/day/28 days) ( N = 60) or parenteral antimony (15-20 mg/Sb/kg/day/20 days) ( N = 30) according to age groups: 2-12 y/o and 13-65 y/o. Patients were human immunodeficiency virus (HIV) noninfected parasitological proven CL without previous treatment. Definitive cure was accessed at 6 months follow-up visit. No severe adverse events occurred. Vomiting was the most frequent adverse event (48.3%) followed by nausea (8.6%) and diarrhea (6.7%). Cure rates were 71.4% (95% confidence interval [CI] = 57.8-82.7) and 53.6% (95% CI = 33.9-72.5) ( P = 0.05) for miltefosine and antimonial, respectively. There were no differences in cure rates between age groups within the same treatment arms. Miltefosine was safe and relatively well tolerated and cure rate was higher than antimony. Copyright © 2011 by The American Society of Tropical Medicine and Hygiene.
Machado P.R.,Federal University of Bahia |
Ampuero J.,University of Brasilia |
Guimaraes L.H.,Federal University of Bahia |
Villasboas L.,Federal University of Bahia |
And 6 more authors.
PLoS Neglected Tropical Diseases | Year: 2010
Background: Cutaneous leishmaniasis (CL) is treated with parenteral drugs for decades with decreasing rate cures. Miltefosine is an oral medication with anti-leishmania activity and may increase the cure rates and improve compliance. Methodology/Principal Findings: This study is a randomized, open-label, controlled clinical trial aimed to evaluate the efficacy and safety of miltefosine versus pentavalent antimony (Sbv) in the treatment of patients with CL caused by Leishmania braziliensis in Bahia, Brazil. A total of 90 patients were enrolled in the trial; 60 were assigned to receive miltefosine and 30 to receive Sbv. Six months after treatment, in the intention-to-treat analyses, the definitive cure rate was 53.3% in the Sbv group and 75% in the miltefosine group (difference of 21.7%, 95% CI 0.08% to 42.7%, p=0.04). Miltefosine was more effective than Sbv in the age group of 13-65 years-old compared to 2-12 years-old group (78.9% versus 45% p= 0.02; 68.2% versus 70% p= 1.0, respectively). The incidence of adverse events was similar in the Sbv and miltefosine groups (76.7% vs. 78.3%). Vomiting (41.7%), nausea (40%), and abdominal pain (23.3%) were significantly more frequent in the miltefosine group while arthralgias (20.7%), mialgias (20.7%) and fever (23.3%) were significantly more frequent in the Sbv group. Conclusions: This study demonstrates that miltefosine therapy is more effective than standard Sbv and safe for the treatment of CL caused by Leishmania braziliensis in Bahia, Brazil. © 2010 Machado et al.
Siqueira A.M.,Fundacao de Medicina Tropical do Amazonas |
Alexandre M.A.A.,Fundacao de Medicina Tropical do Amazonas |
Mourao M.P.G.,Fundacao de Medicina Tropical do Amazonas |
Santos V.S.,Fundacao de Medicina Tropical do Amazonas |
And 3 more authors.
American Journal of Tropical Medicine and Hygiene | Year: 2010
Severe rhabdomyolysis (creatine Phosphokinase = 29,400U/L) developed in a 16-year-old boy from Manaus, Brazil, after he started treatment with chloroquine for infection with Plasmodium vivax. Treatment led to myoglobinuria and acute renal failure. After hemodialysis, the patient improved and a muscle biopsy specimen showed no myophosphorylase or deaminase deficiency. This case of rhabdomyolysis associated with P vivax infection showed no comorbidities. The pathogenesis is still unclear. Copyright © 2010 by The American Society of Tropical Medicine and Hygiene.
Bueno L.L.,Federal University of Minas Gerais |
Morais C.G.,Federal University of Minas Gerais |
Araujo F.F.,Instituto Rene Rachou |
Gomes J.A.S.,Instituto Rene Rachou |
And 7 more authors.
PLoS ONE | Year: 2010
Circulation CD4+CD25+FoxP3+ regulatory T cells (Tregs) have been associated with the delicate balancing between control of overwhelming acute malaria infection and prevention of immune pathology due to disproportionate inflammatory responses to erythrocytic stage of the parasite. While the role of Tregs has been well-documented in murine models and P. falciparum infection, the phenotype and function of Tregs in P. vivax infection is still poorly characterized. In the current study, we demonstrated that patients with acute P. vivax infection presented a significant augmentation of circulating Tregs producing anti-inflammatory (IL-10 and TGF-β) as well as pro-inflammatory (IFN-γ, IL-17) cytokines, which was further positively correlated with parasite burden. Surface expression of GITR molecule and intracellular expression of CTLA-4 were significantly upregulated in Tregs from infected donors, presenting also a positive association between either absolute numbers of CD4+CD25+FoxP3+GITR + or CD4+CD25+FoxP3+CTLA-4 + and parasite load. Finally, we demonstrate a suppressive effect of Treg cells in specific T cell proliferative responses of P. vivax infected subjects after antigen stimulation with Pv-AMA-1. Our findings indicate that malaria vivax infection lead to an increased number of activated Treg cells that are highly associated with parasite load, which probably exert an important contribution to the modulation of immune responses during P. vivax infection. © 2010 Bueno et al.
Alexandre M.A.,Fundacao de Medicina Tropical do Amazonas |
Alexandre M.A.,University of the State of Amazonas |
Alexandre M.A.,Centro Universitario Nilton Lins |
Ferreira C.O.,Fundacao de Medicina Tropical do Amazonas |
And 11 more authors.
Emerging Infectious Diseases | Year: 2010
We describe a case series of 17 patients hospitalized in Manaus (western Brazilian Amazon) with PCR-confi rmed Plasmodium vivax infection who were treated with chloroquine and primaquine. The major complications were jaundice and severe anemia. No in vivo chloroquine resistance was detected. These data help characterize the clinical profi le of severe P. vivax malaria in Latin America.
Talhari S.,Fundacao de Medicina Tropical do Amazonas |
de Souza Santos M.N.,Fundacao de Medicina Tropical do Amazonas |
Talhari C.,Fundacao de Medicina Tropical do Amazonas |
de Lima Ferreira L.C.,Fundacao de Medicina Tropical do Amazonas |
And 4 more authors.
Acta Tropica | Year: 2010
In the present study, we report the occurrence of Lyme's borreliosis in patients from the Brazilian Amazon Region. Borreliosis was investigated by immunohistochemistry and focus floating microscopy for Borrelia burgdorferi in skin biopsy samples from 22 patients with both clinical and histopathology evidences compatible with Erythema Migrans. Spirochetes were detected by specific immunohistochemistry and focus floating microscopy for B. burgdorferi in samples from five patients. Clinical cure of the cutaneous lesions was observed in all the patients after treatment with doxycycline regimen as proposed by the Center Disease Control guidelines. A limitation of our study was the fact that we were not able to isolate and culture these organisms. These are the first known Brazilian cases of borreliosis to have Focus Floating Microscopy confirmation. © 2010 Elsevier B.V.